#include<bits/stdc++.h>
using namespace std;

#define int long long

signed main()
{
	int A, B;
	cin >> A >> B;
	int ans = max(A, B) - min(A, B) - 1;
	if (A > B) ans += 2000000000 - A;
	else ans += A - 1;
	printf("%lld\n", ans);
	return 0;
}